Method and device for improving spontaneous radiation time contrast of femtosecond laser pulse

Abstract

The invention discloses a method and a device for improving spontaneous radiation time contrast of femtosecond laser pulses. The device comprises a titanium sapphire femtosecond laser oscillator, a laser pumping source, a stretcher, a regenerative amplifier, an electro-optical switch, a compressor and the like. The low-energy pulse output by the femtosecond laser oscillator broadens the time domain of the laser pulse after passing through the stretcher, then the laser pulse is sent to the regenerative amplifier to be amplified, and at the moment, the transmissivity of the laser pulses with different wavelengths in the annular cavity is adjusted by adjusting the incident angle of the laser entering the frequency spectrum shaping filter in the annular cavity, so that spontaneous radiation in the cavity is inhibited, and the spontaneous radiation time contrast of the amplified light is improved. And then the femtosecond laser is controlled by an electro-optical switch to enter a pulse compressor, and finally femtosecond laser pulses with high energy and high time contrast are generated. According to the femtosecond laser amplifier, the spontaneous radiation time contrast of femtosecond laser pulses is improved through frequency spectrum shaping and filtering in the annular cavity of the amplifier, meanwhile, spectrum red shift and gain narrowing of amplified light can be effectively restrained, and the amplified light with the wide spectrum is output.

Description

Technical field [0001] The present invention belongs to the field of ultra-fast laser amplifiers, and more particularly to the field of ultra-fast laser amplifier, and more particularly to a method of improving femtosecond laser pulse spontaneous radiation time contrast and means for implementing the method. Background technique [0002] The proposal of Chirped-Pulse Amplification, referred to as CPA, solves bottleneck problems that cannot break through the laser peak power, providing an effective way for the development of ultra-short super-laser. The development of ultra-short super laser greatly promotes the progress of extreme physical experiments such as X-rays, inertial constraints, and laser ion accelerators. [0003] In a general CPA laser system, since the spontaneous radiation produced by itself is not enough, it is not possible to cause the amplified laser pulse in the background noise, which mainly includes ASE. And the pre-pulse of the laser frontier and the like. Th...

AI Technical Summary

Problems solved by technology

However, this technology is not only complicated to operate, but also unable to compensate for the spectral red shift and gain narrowing of the amplified light.

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